Presentation by Ray Myers of the Asphalt Interlayer Association on interlayers and geosynthetics delivered at the CalAPA Fall Asphalt Pavement Conference held Oct. 24, 2013 in Sacramento, Calif.

1. Ray Myers
Executive Director of the Asphalt
Interlayer Association
www.info@aia-us.org
916-933-9140
“Using
Geosynthetics with
Flexible Pavement Systems”

2. THERE ARE SO MANY
OPPORTUNITIES FOR
INFRASTRUCTURE
IMPROVEMENTS, COST SAVINGS
& INCREASED PROFITS
USING GEOSYNTHETICS
BELOW AND IN HMA/WMA

3. GEOSYNTHETICS
BELOW
Woven Geotextiles
Nonwoven Geotextile
Subgrade Geogrids
IN
Paving Fabrics
Paving Mats
Paving Grids
Composite Paving Grids
Composite Drainage Products

4. What’s new?
 Caltrans Section reduction with Geosynthetics
 2009 Subgrade Geotextiles
 2012 Subgrade Geogrids
 GRCS Geosynthetic Reinforced Chip Seal
 UCDavis study on light reflection with GRCS
 New products by Geosynthetic Manufacturers
 NTPEP National Transportation Product Evaluation
Program
 Paving Fabric Bonding Agent [details from AIA]

13. Guide for Designing with Subgrade
Enhancement Geotextiles
Geotextiles[SEG’s] - 2009
Geogrids [ABEG’s] -2012
http://www.dot.ca.gov/hq/maint/Paveme
nt/Offices/Pavement_Engineering/PDF/
Subgrade_Enhancement_Geosynthetic_
Design_and_Construction_Guide.pdf

14. Woven Geotextiles

15. Nonwoven Geotextiles

16. Geogrid for Base Reinforcement and
Subgrade Stabilization

17. Most engineers/field personnel have
used Geosynthetics (Grids and
Geotextiles) to bridge unsuitable soils
when they were encountered on the
jobsite
However, now we have the tools to
proactively design
for those conditions!

18. FHWA summary of factors
that affect pavement life
1.
2.
3.
4.
5.
6.
Water
Traffic Load
Subgrade Quality
Maintenance
Age
Quality of Construction

19. Factors Affecting Pavement
Life
1. Water creates 80% of the
problems
2. Traffic Load
3. Subgrade Quality
4. Maintenance
5. Age
6. Quality of Construction

20. When water is present in
the aggregate base traffic
loading moves fines up &
contaminates the aggregate
base
Fines lower the load
bearing capacity of that
aggregate base.

21. REED & GRAHAM INC.

22. Ways in which Water Enters the Road
Through Permeable Surface
Lateral Flow
from Roadside
Water Table
Seepage from
High Ground
Capillary Flow

23. To mitigate the impacts of
water on a pavement
section:
• Water (Side) Edge Drains
• Water (Bottom) SEG’s
• Water (Top) Interlayers

24. To mitigate the impacts of
water on a pavement
section:
•Water (Side)
Edge Drains
• Water (Bottom) SEG’s
• Water (Top) INTERLAYERS

25. Filtration: Typically Nonwoven

27. REED & GRAHAM INC.

29. To mitigate the impact of
water on a pavement
section coming from:
•
(Top, Side, Bottom) Edge Drains
•(Bottom) use SEG’s
Subgrade Enhancement Geotextiles
•
(Top) Interlayers

30. Separation Application

31. What happens
Under the pavement ?

34. 1. Separation
Now
2. Stabilization

35. Stabilization Application

37. Biaxial Geogrid
Property
Test
Value
Aperture size, incha
min and max
Calipered
0.8-1.3 x 1.0-1.6
Rib thickness, inch
min
Calipered
0.04
Junction thickness, inch
min
Calipered
0.150
Tensile strength, 2% strain, lb/fta
min
ASTM D 6637
410 x 620
Tensile strength at ultimate, lb/fta
min
ASTM D 6637
1,310 x 1,970
ASTM D 4355
100
Junction strength, lb/fta
min
ASTM D 7737
1,220 x 1,830
Overall flexural rigidity, mg-cm
min
ASTM D 7748
750,000
GRI:GG9
0.65
Ultraviolet resistance, percent
min retained tensile strength, 500 hours
Torsional rigidity at 20 cm-kg, mm-kg/degb
min
aMachine
direction x cross direction
Research Institute, Test Method GG9, Torsional Behavior of Bidirectional Geogrids When Subjected to In-Plane Rotation
bGeosynthetic

38. Section Reduction
with the use of a Geotextile
and or a Geogrid produce
alternate designs that can
reduce Aggregate Base
by as much as 30%!
Cost Optimization

39. A
B
C
D
E
F
G
H
I
J
K
L
M
Traffic Index
9.5
9.5
9.5
9.5
9.5
9.5
9.5
9.5
9.5
9.5
9.5
9.5
9.5
% Trucks
8%
8%
8%
8%
8%
8%
8%
8%
8%
8%
8%
8%
8%
% Growth
4%
4%
4%
4%
4%
4%
4%
4%
4%
4%
4%
4%
4%
R-value
10
10
10
10
10
10
10
10
10
10
10
10
10
Drain Coeff.
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
AC/AGG
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
A/C $/ton
$75
$75
$75
$75
$75
$75
$75
$75
$75
$75
$75
$75
$75
BASE $/ton
$40
$40
$40
$40
$40
$40
$40
$40
$40
$40
$40
$40
$40
$1.50
$1.50
$1.50
$1.50
$1.50
$1.50
$1.50
$1.50
$1.50
$1.50
$1.50
$1.50
$1.50
Required #
5.71
5.71
5.71
5.71
5.71
5.71
5.71
5.71
5.71
5.71
5.71
5.71
5.71
Design #
5.71
5.71
5.73
5.73
5.74
5.74
5.77
5.77
6.0
6.0
6.0
6.5
6.5
6.5
7.0
7.0
7.0
8.0
8.0
8.0
9.0
BASE (")
21.5
17.0
21.0
20.0
15.5
20.0
18.5
13.5
18.5
15.5
10.5
15.5
7.0
Sect.total
27.5
23.0
27.0
26.5
22.0
26.5
25.5
20.5
25.5
23.5
18.5
23.5
16.0
SEG/$SY
ASPHALT (")
SEG Y/N
N
HSW
Cost/LnM$
$1.14M
$1,006
Excav $k's
$1.3M
$1,122
20
HSW
Design Life
Cost Savings %
Save k$/ln mile
N
HSW
$1,121
$979
$1,314
$1,254
$1,090
20
35
20
12.7%
-2.1%
$164
($28)
HSW
N
HSW
$1,092
$932
$1,281
$1,222
$1,037
20
35
20
2.5%
15.2%
0.3%
$32
$196
$5
HSW
N
HSW
5.73
HSW
HSW
$799
$1,037
$878
$1,249
$1,157
$972
$1,18
4
$880k
20
35
20
20
35
20
5.0%
19.3%
2.9%
10.0%
24.4%
7.9%
31.6%
$64
$249
$37
$129
$314
$102
$400k

40. CALTRANS
HWY 53
CLEARLAKE, CA
01-3986A4
~$150,000 to the
contractor

41. We’ve covered
Geosynthetics BELOW
the pavement
Now Geosynthetics
IN the pavement

42. Caltrans MTAG
http://www.dot.ca.gov/hq/maint/MTA_GuideVolume1Flexible.html
Types of Interlayers
Material Specifications
Design Criteria
Application Rates

43. DETERMINE
TYPE AND
LEVEL OF
DISTRESS!!!!

44. Unacceptable pavement conditions to
utilize interlayers








Rutting Internal
Rutting due to unsatisfactory base
Loose Asphalt
Inadequate structure
Standing water
Excess traffic
Quality of milling
Lack of preparation

45.  Rutting or shoving AC

47. Unacceptable Grinding for most
interlayers

48. Finish/Profile Grinding

49. Factors Affecting Pavement
Life
1. Water creates 80% of the
problems
2. Traffic Load
3. Subgrade Quality
4. Maintenance
5. Age
6. Quality of Construction

50. Why Use Interlayers?
To provide an extension of pavement life by doing one or more of the
following:
1. Reduce the pavement
permeability by creating a
moisture barrier
2. Reduce reflective cracking
3. Provide stress relief
4. Reinforcement

51. When to use Interlayers?
 new construction,
 rehabilitation or
 preservation
in conjunction with
an overlay or
surface treatment

52. Types of
Interlayers
 Fabric - Polypropylene
 Mat - Polyester/Fiberglass
 Grids
 Non Composite
 Composite
 Peel & Stick Membranes

53. Paving Fabric
 Paving Fabric: A non-woven geotextile
fabric that is saturated with asphalt cement
and placed with an overlay or chip seal.

56. Warm Mix with Paving Fabric

57. GRCS
Geosynthetic Reinforced Chip Seals
The specifications differ from that of fabric
under an overlay
Go to www.aia-us.org
This process is used world wide
Successful GRCS Projects that
have been in place for 25
years and yet to require
additional treatment.

58. GRCS: Terminal Blend
Rubber Chip Seal over
Paving Fabric

61. Paving Mat

62. Pavement Reinforcing Grid
 Very high strength
 50kN = 11240 pounds force
 100kN = 22480 pounds force
 200kN = 44960 pounds force
That is why the term reinforcing is appropriate

63. Mill & Fill Failure

64. Pavement Reinforcing Composite
Grid

66. MULTI-AXIAL COMPOSITE PAVING GRID

67. Recycling Paving Fabric

68. Can Asphalt with Paving fabric
be Recycled?
ABSOLUTELY!!!!!
“Syracuse Revisited”
Aia-us.org
Consider Pavement
Fabric Bonding Agent

69. To Recycle the system must
be installed correctly

71. How much binder has been placed?

72. Post weigh test unit

73. Non Composite
Paving Grid

77. Composite Membranes

78. NTPEP
National Transportation Product Evaluation Program
Developed in 2010/2011 in part through then
leadership of an AIA member
Allows states to get away from traditional
APL/QPL’s
Enables inspectors to be certain which
product is being used

79. ·Product
name
·Manufacturer
·Location manufactured
·AASHTO/NTPEP reference
if applicable

81. THINK INSIDE THE GREEN BOX WITH
HMA, WMA & GRCS TO BUILD PAVEMENTS
THAT:
A. LESS EXPENSIVE
B. LAST LONGER
C. USE LESS NATURAL RESOURCES
D. GENERATE MORE PROFIT
SO MANY BENEFITS OF THE ALLIANCE OF
ASPHALT & GEOSYNTHETICS WHETHER
BELOW OR IN THE PAVEMENT SECTION

82. Ray Myers
Executive Director of the
Asphalt Interlayer Association
www.info@aia-us.org
916-933-9140
“Using
Geosynthetics with
Flexible Pavement Systems”